作业帮已知x-y=9,xy=5.求(x+y)(x+y)的值?
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/13 11:22:01
已知x-y=9,xy=5.求(x+y)(x+y)的值?
已知x-y=9,xy=5.求(x+y)(x+y)的值?
已知x-y=9,xy=5.求(x+y)(x+y)的值?
x-y=9
(x-y)²=9²
x²-2xy+y²=81
x²+y²=81+2xy=91
所以(x+y)²
=x²+y²+2xy
=91+10
=101
(x+y)(x+y)=（x-y)^2+4xy=9*9+4*5=101
x-y=9
(x-y)²=9²
x²-2xy+y²=81
x²+y²=81+2xy=91
所以(x+y)²
=x²+y²+2xy
=91+10
=101
(x+y)^2=(x-y)^2+4xy=81+20=101
(x+y)(x+y)
=(x+y)²
=(x-y)²+4xy
=81+20
=101
(x+y)(x+y)
=(x+y)²
=x²+2xy+y²
=x²-2xy+y²+4xy
=(x-y)²+4xy
已知x-y=9,xy=5
所以上式=9²+4*5
=81+20
=101
x-y=9 方程两边平方推出 x∧2+y∧2=81+2xy=91 所以 (x+y)(x+y)=x∧2+y∧2+2xy=91+10=101
已知x-y=9,xy=5.求(x+y)(x+y)的值?
已知x-xy=8,xy-y=-9,求x+y-2xy的值
已知x-y=9,xy=负20,求（x+y)(x+y)
已知x^2-6xy+9y^2=0,求(x-y)/(x+y)
已知x+y=12,xy=9,求(x+3xy+y)/(xy+xy)的值
已知(1/x)-(1/y)=5,求(6x+7xy-6y)/(8y-9xy-8y)
已知(x+y)(x+y)=25,(x-y)(x-y)=9求xy与xx+yy的值
已知,1/x+1/y=5.,求分式3x+xy+3y/x-2xy+y的值
已知 1/x-1/y=5.求(2x+4xy-2y)/(x-3xy-y)
已知x+y+yz=5,y+z+xy=8,x+z+xy=9,求x,y,z
已知X+Y=3,XY=-1,求2(X-Y)^4-9(X-Y)^2+12XY
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
已知x^2+xy=16 y^2+xy=9 求(x+y) (x-y)分别是 x+y x-y 不是乘
已知：x(x-50y)+xy=50y^2,求：(x-y):y=?
已知x+y=-1,xy=-2,求代数式-5（x+y)+(x-y)+x(xy+y)的值
已知,x²+xy=14,y²+xy=2(x>y>0)求x+y.x-y
已知,x²+xy=14,y²+xy=2(x>y>0)求x+y.x-y
已知,x²+xy=14,y²+xy=2(x>y>0)求x+y.x-y